Universal Joint

ABSTRACT

A universal joint includes a spider, first and second yokes drivingly interconnected by the spider, a plurality of bearing cups and a plurality of retaining members. The first yoke includes spaced apart arms with apertures extending through each arm. The apertures are coaxially aligned with one another and include a circumferential groove spaced apart from an edge of the arm. Each bearing cup is positioned within one of the apertures and in receipt of one of the trunnions. A portion of each bearing cup is positioned in communication with a corresponding groove. Each retaining member is operable to complement the size and shape of the corresponding groove, bearing cup and aperture such that each retaining member couples one of the bearing cups to its associated arm.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a continuation application of co-pending U.S. patent applicationSer. No. 11/062,934 filed Feb. 22, 2005. The entire disclosure of theabove application is incorporated by reference herein.

BACKGROUND OF THE INVENTION

The present invention generally relates to a universal joint for use ina driveline of a motor vehicle. More specifically, the present inventionpertains to a universal joint equipped with a retention member forsecuring a bearing cup in a yoke.

As is commonly known, universal joints are used in motor vehicledriveline applications for interconnecting a pair of rotary shafts andpermitting changes in angularity therebetween. Many conventionaluniversal joints include a pair of bifurcated yokes which are secured tothe rotary shafts. The bifurcated yokes are interconnected by a spideror a cruciform for rotation about independent axes. The spider includesfour orthogonal trunnions with each opposing pair of axially alignedtrunnions mounted in a pair of aligned bores formed in the bifurcatedyokes. Typically, a bearing cup is secured in each bore and a bearingassembly is retained in the bearing cup such that each yoke is supportedfor pivotal movement relative to one of the pairs of trunnions.

Various retention methods have been developed for securing the bearingcups to the yokes in a manner wherein the rotary axis of each yoke isaligned centrally with respect to the rotary axis of the spider.Traditional bearing cup retention methods include the use of grooves andplanar snap rings. In particular, one type of conventional universaljoint utilizes a planar snap ring seated in a circumferential groovemachined into the bore formed in the yokes for axially retaining thebearing cups. However, due to the dimensional variations within eachcomponent, either an interference condition or an excess clearancebetween the bearing cup and the snap ring is accumulated. If aninterference condition exists, one or both of the bifurcated yokes ismechanically deformed to increase the spacing between the previouslymachined grooves. If an excess clearance condition exists, relativemotion may occur between the bearing cup and yoke bores, resulting innoise or vibration during use. Alternatively, an assembler may beprovided with a plurality of snap rings having different thicknesses.The assembler uses a trial and error method to fit the largest snap ringpossible within the clearance. Unfortunately, the universal jointassembled by these technologies may not be as rotationally balanced asdesired.

SUMMARY OF THE INVENTION

Accordingly, the present invention is directed to overcoming thedisadvantages commonly associated with the manufacture and balancing ofconventional universal joints. Therefore, it is an object of the presentinvention to reduce the number of components and cost required toconstruct a balanced universal joint assembly.

The present invention is directed to a universal joint including aspider, first and second yokes drivingly interconnected by the spider, aplurality of bearing cups and a plurality of retaining members. Thefirst yoke includes spaced apart arms with apertures extending througheach arm. The apertures are coaxially aligned with one another andinclude a circumferential groove spaced apart from an edge of the arm.Each bearing cup is positioned within one of the apertures and inreceipt of one of the trunnions. A portion of each bearing cup ispositioned in communication with a corresponding groove. Each retainingmember is operable to complement the size and shape of the correspondinggroove, bearing cup and aperture such that each retaining member couplesone of the bearing cups to its associated arm.

The method of assembling the universal joint includes providing a yokewith a pair of arms where each of the arms has a trunnion aperture. Atrunnion is installed into each trunnion aperture. A plurality ofbearing cups are installed such that each bearing cup is received intoone of the trunnion apertures and received onto an associated trunnion.Molten polymeric resin is injected into a groove formed in each of thearms. The groove is positioned adjacent to an associate bearing cup. Themolten resin is allowed to cool to form a retaining member coupling eachbearing cup to its associated arm.

Further areas of applicability of the present invention will becomeapparent from the detailed description provided herein after. It shouldbe understood however that the detailed description and specificexamples, while indicating preferred embodiments of the invention, areintended for purposes of illustration only since various changes andmodifications within the spirit and scope of the invention will becomeapparent to those skilled in the art from this detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from thedetailed description and the accompanying drawings, wherein:

FIG. 1 is a perspective view of a universal joint according to theprincipals of the present invention;

FIG. 2 is an exploded perspective view of the universal joint shown inFIG. 1;

FIG. 3 is a sectional view of the retention member shown in FIG. 1; and

FIG. 4 is a partial sectional view of one of the yokes associated withthe universal joint shown in FIGS. 1-3.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

In general, the present invention is directed to a universal joint ofthe type used in motor vehicle driveline applications forinterconnecting rotating shafts in a manner permitting changes inangularity therebetween.

Referring to FIGS. 1 and 2, a universal joint 10 is shown connecting afirst shaft 12 to a second shaft 14. In general, universal joint 10includes a first yoke 16 attached to an end of first shaft 12, a secondyoke 18 attached to an end of second shaft 14 and a spider or cruciform20 interconnecting first yoke 16 to second yoke 18. The first yoke 16 isbifurcated and includes a pair of laterally spaced-apart legs 22 whichare preferably symmetrical with respect to the rotary axis of firstshaft 12, as denoted by construction line A. Legs 22 include an inboardsurface 24 and an outboard surface 26 with an aperture 28 extendingtherebetween. Apertures 28 are aligned on a first trunnion axis, asdenoted by construction line Y, which passes through and is orthogonalwith respect to rotary axis A of first shaft 12. Each aperture 28 is athroughbore and includes an annular ring groove 30 positioned betweenthe inboard surface 24 and the outboard surface 26.

Second yoke 18 is bifurcated and includes a pair of laterally-spacedlegs 32 which are preferably symmetrical with respect to the rotary axisof second shaft 14, as denoted by construction line B. Legs 32 includean inboard surface 34 and an outboard surface 36 with an aperture 38extending therebetween. Apertures 38 are aligned on a second trunnionaxis, as denoted by construction line Z, which passes through and isorthogonal with respect to rotary axis B of second shaft 14. Apertures38 are throughbores which include an annular groove 40 formed betweenthe inboard surface 34 and the outboard surface 36. It should be notedthat the shape and dimensions of apertures 28 and 38 may either beidentical or different depending on the particular dimensions ofcruciform 20 used therewith. It should also be noted that the annularring grooves 30 and 40 may be formed by machining, casting or by similartechnique.

As best seen in FIG. 2, cruciform 20 includes a central hub 42 fromwhich a pair of first trunnions 44 and a pair of second trunnions 46extend. First trunnions 44 are orthogonal with respect to secondtrunnions 46. First trunnions 44 are adapted for insertion intoapertures 28 in legs 22 of first yoke 16 so as to be axially aligned onfirst trunnion axis Y. Similarly, second trunnions 46 are adapted to beinserted into apertures 38 in legs 32 of second yoke 18 so as to beaxially aligned on second trunnion axis Z. With first trunnions 44 andsecond trunnions 46 installed in first and second yokes 16 and 18,respectfully, trunnion axes Y and Z pass through a common plane whichorthogonally intersects the rotary axis of cruciform 20, shown in FIG. 1by construction plane C.

Universal joint 10 also includes a first pair of bearing cups 48 adaptedto be mounted in apertures 28 and a second pair of bearing cups 50adapted to be mounted in apertures 38. First bearing cups 48 areprovided for receiving and rotatably supporting first trunnions 44 inapertures 28. Similarly, second bearing cups 50 are provided forreceiving and rotatably supporting second trunnions 46 in apertures 38.As seen, bearing cups 48 and 50 each include a tubular sleeve segment 49enclosed by an end segment 51. A roller bearing assembly 52 is mountedin the sleeve segment for rotatably supporting trunnions 44 and 46therein. In addition, annular elastomeric seals 54 are mounted ontrunnions 44 and 46, respectively, for providing a sealed relationshipwith respect to the open end of the sleeve segments 49 of bearing cups48 and 50, respectively.

To assemble the universal joint 10, one of the bearing cups 48 ismounted on one of the first trunnions 44 prior to insertion thereof intoits corresponding aperture 28 such that the terminal end surface of thetrunnion is placed in abutting engagement with the end segment 51 of itscorresponding bearing cup. Alternatively, trunnions 44 and 46 may beinstalled into corresponding apertures 28 and 38 with bearing cups 48and 50 thereafter installed into apertures 28 and 38. For purposes ofdescribing the cruciform alignment and retention device used inassociation with yokes 16 and 18, reference is now directed to FIG. 3.However, while the following disclosure is specifically directed toretention of cruciform 20 relative to first yoke 16, it is to beunderstood that a similar process is contemplated for use with secondyoke 18.

Once rotary axis A of first shaft 12 is co-axially aligned with rotaryaxis B of second shaft 14, a retention member 60 cooperates with eachbearing cup 48 to retain the afore-mentioned components in relation toeach other. FIG. 3 depicts retention member 60 as including a polymericring 62 injection molded into engagement with an end face 64 of bearingcup 48. Molten polymeric material substantially fills ring groove 30.Ring groove 30 has a width sized to axially overlap at least a portionof an outer cylindrical wall 66 of sleeve segment 49. In this manner, atleast a portion of polymeric ring 62 circumferentially surrounds bearingcup 48. Furthermore, end face 64 of bearing cup 48 lies in a planeintersecting groove 30. Also, a portion of retention member 60 extendsaxially beyond end face 64 in a direction away from the spider. Afterthe molten resin is injected to fill the annular groove 30 as previouslydescribed, the resin is cooled. During cooling, the polymeric materialshrinks slightly causing an inner surface 68 of polymeric ring 62 toengage and grip a portion of outer cylindrical wall 66. Therefore,polymeric ring 62 functions as an anti-rotational device to resistrelative rotation between bearing cup 48 and leg 22.

As shown in FIGS. 3 and 4, polymeric ring 62 further includes a lug 70integrally formed with polymeric ring 62. Lug 70 is formed when moltenresin fills an undercut or recess 72 machined in communication withgroove 30. Undercut 72 axially extends from an edge of groove 30.Undercut 72 may radially extend a distance less than or equal to theradius of groove 30. Undercut 72 circumferentially extends an arc lengthless than the entire circumference of groove 30. Lug 70 and undercut 72cooperate to further provide an anti-rotational device restrictingpolymeric ring 62 from rotation relative to leg 22. Polymeric ring 62includes an outer cylindrical surface 74 and an aperture 76 extendingtherethrough. Aperture 76 exposes end segment 51 to the atmosphere.

Polymeric ring 62 may be constructed from a variety of materialsincluding nylon, glass-filled nylon, or other injection moldablethermoplastics. These materials have sufficient strength to resist axialmovement of bearing cup 48 relative to leg 22 during operation of theuniversal joint. However, the polymeric ring material has a shearstrength which allows bearing cup 48 to be removed from aperture 28 anddisconnected from leg 22 to allow the universal joint to be serviced. Itis contemplated that the retention member is operable to be sheared intoat least two pieces by application of force to the spider to allow thebearing cups to translate within the apertures and disassemble theuniversal joint. Because the joint was originally equipped with ringgroove 30, the joint may be serviced and reassembled using a standardplanar snap ring (not shown).

Therefore, it should be appreciated that the configuration and operationof universal joint 10 provides both manufacturing and functionaladvantages over the prior art. Specifically, the universal joint 10 ofthe present invention utilizes a retention member formed by an injectionmolding process to automate assembly and increase the likelihood ofproducing a properly aligned and balanced universal joint. Additionallythe cost and time required for manufacturing the universal joint arereduced.

While the invention has been described in the specification andillustrated in the drawings with reference to a preferred embodiment, itwill be understood by those skilled in the art that various changes maybe made and equivalents may be substituted for elements thereof withoutdeparting from the scope of the invention as defined in the claims. Inaddition, many modifications may be made to adapt a particular situationor material to the teachings of the invention without departing from theessential scope thereof. Therefore, it is intended that the inventionnot be limited to the particular embodiment illustrated by the drawingsand described in the specification as the best mode presentlycontemplated for carrying out this invention, but that the inventionwill include any embodiments falling within the description of theappended claims.

1. A shaft assembly, comprising: a first shaft having a first yoke, saidfirst yoke including a first aperture having a first groove and a recesscommunicating with said first groove; a second shaft having a secondyoke, said second yoke including a second aperture having a secondgroove; a spider having a first trunnion positioned within said firstaperture of said first yoke and a second trunnion positioned within saidsecond aperture of said second yoke; a first bearing cup mounted on saidfirst trunnion within said first aperture; a second bearing cup mountedon said second trunnion within said second aperture; and a firstretention member that is formed in-situ following solidification of amolten polymeric material injected into said first groove and saidrecess such that a lug is formed within said recess.
 2. The shaftassembly of claim 1 wherein said first retention member includes a firstring segment disposed within said first groove which engages a tubularsegment of said first bearing cup, and a second ring segment connectedto said first ring segment and which engages an end plate segment ofsaid first bearing cup, and wherein said lug extends from said firstring segment of said first retention member.
 3. The shaft assembly ofclaim 2 wherein said first bearing cup is positioned within said firstaperture such that its end plate segment is aligned with said firstgroove.
 4. The shaft assembly of claim 2 wherein said second ringsegment of said first retention member includes an aperture exposing aportion of said end plate segment of said first bearing cup toatmosphere.
 5. The shaft assembly of claim 2 wherein an outer wallsurface of said tubular segment of said first bearing cup engages aninner wall surface of said first aperture such that said first segmentof said first retention member engages a portion of said outer wallsurface that is aligned with said first groove.
 6. The shaft assembly ofclaim 1 further including a second retention member formed in-situfollowing solidification of a molten polymeric material injected intosaid second groove.
 7. The shaft assembly of claim 1 wherein said recesscommunicates with said first groove and extends axially beyond an edgeof said first groove.
 8. The shaft assembly of claim 7 wherein saidrecess extends circumferentially about an arc length that is less thanthe entire circumference of said first groove.
 9. The shaft assembly ofclaim 7 wherein said recess has an arcuate shape with a radius that issmaller than the radius of said first groove.
 10. A shaft assembly,comprising: a first shaft; a second shaft; and a universal jointinterconnecting said first and second shafts, said universal jointincluding a first yoke fixed for rotation with said first shaft andhaving a first aperture defining a first annular groove, a second yokefixed for rotation with said second shaft and having a second aperturedefining a second annular groove, a spider having a first trunniondisposed in said first aperture and a second trunnion disposed in saidsecond aperture, a first bearing cup mounted on said first trunnionwithin said first aperture, a second bearing cup mounted on said secondtrunnion within said second aperture, and first and second retentionmembers formed in-situ upon solidification of a molten polymericmaterial injected into said first and second grooves, wherein said firstaperture includes a discrete recess extending outwardly from an edge ofsaid first groove such that an anti-rotation lug is formed therein uponsolidification of said molten polymeric material.
 11. The shaft assemblyof claim 10 wherein said first retention member includes a first ringsegment disposed within said first groove which engages a tubularsegment of said first bearing cup, and a second ring segment connectedto said first ring segment and which engages an end plate segment ofsaid first bearing cup, and wherein said lug extends from said firstring segment of said first retention member.
 12. The shaft assembly ofclaim 11 wherein said first bearing cup is positioned within said firstaperture such that its end plate segment is aligned with said firstgroove.
 13. The shaft assembly of claim 11 wherein said second ringsegment of said first retention member includes an aperture exposing aportion of said end plate segment of said first bearing cup toatmosphere.
 14. The shaft assembly of claim 11 wherein an outer wallsurface of said tubular segment of said first bearing cup engages aninner wall surface of said first aperture such that said first segmentof said first retention member engages a portion of said outer wallsurface that is aligned with said first groove.
 15. The shaft assemblyof claim 10 wherein said recess communicates with said first groove andextends axially beyond said edge of said first groove.
 16. The shaftassembly of claim 10 wherein said recess extends circumferentially aboutan arc length that is less than the entire circumference of said firstgroove.
 17. The shaft assembly of claim 10 wherein said recess has anarcuate shape with a radius that is smaller than the radius of saidfirst groove.
 18. A shaft assembly, comprising: a first shaft; a secondshaft; and a universal joint interconnecting said first and secondshafts, said universal joint including a first yoke fixed for rotationwith said first shaft and having a first aperture defining a firstannular groove, a second yoke fixed for rotation with said second shaftand having a second aperture defining a second annular groove, a spiderhaving a first trunnion disposed in said first aperture and a secondtrunnion disposed in said second aperture, a first bearing cup mountedon said first trunnion within said first aperture, a second bearing cupmounted on said second trunnion within said second aperture, and firstand second retention members formed in-situ upon solidification of amolten polymeric material injected into said first and second grooves,wherein said first retention member engages a planar surface of an endsegment and an outer surface of a tubular sleeve segment of said firstbearing cup.
 19. The shaft assembly of claim 18 wherein said firstretention member includes a first ring segment disposed within saidfirst groove which engages said tubular segment of said first bearingcup, and a second ring segment connected to said first ring segment andwhich engages said end segment of said first bearing cup.
 20. The shaftassembly of claim 19 wherein said first bearing cup is positioned withinsaid first aperture such that its end segment is aligned with said firstgroove.
 21. The shaft assembly of claim 19 wherein said second ringsegment of said first retention member includes an aperture exposing aportion of said end segment of said first bearing cup to atmosphere. 22.The shaft assembly of claim 18 wherein said first aperture includes adiscrete recess formed along an edge of said first groove such that ananti-rotation lug is formed therein upon solidification of said moltenpolymeric material.
 23. The shaft assembly of claim 22 wherein saidrecess communicates with said first groove and extends axially beyondsaid edge of said first groove.
 24. The shaft assembly of claim 22wherein said recess extends circumferentially about an arc length thatis less than the entire circumference of said first groove.
 25. Theshaft assembly of claim 22 wherein said recess has an arcuate shape witha radius that is smaller than the radius of said first groove.